00:01
So when we examine the product of two matrices to see if they are the inverse of each other, this involves just when we multiply, we just want two matrices to equal an identity matrix to prove that they are the inverse of each other.
00:21
So as i'm just writing this out, when you multiply two matrices together, we go across on the left -hand matrixy and down.
00:37
The column on the right -hand matrix.
00:41
So this right -hand matrix is 1 -0 -1, minus 2, 1, and 0 -0.
00:52
So starting on the top left, we have for the, when we multiply, 1 times 1 is 1, 2 times 0 is 0, and 1 times 0 is 0.
01:07
For the middle, we have 1 times minus 2 is minus 2.
01:17
2 times 1 is plus 2 and 0 times 0 is just 0.
01:24
At the top right we have 0, no, 1 times 0, 2 times 0 and 0 times 0 such 0.
01:31
For the middle row on the left we have 0 times 1, which is 0, 1 times 1, 1 times 1.
01:40
0 which is 0 and 0 times 1 which is 0.
01:45
For the middle middle we have the middle row multiplied by the middle column, the second matrix...